ccna4-1 chapter 7-2 chapter 7 ip addressing services part ii

CCNA4-1 Chapter 7-2

Chapter 7Chapter 7

IP Addressing ServicesIP Addressing Services

Part IIPart II

CCNA4-2 Chapter 7-2

IP Addressing ServicesIP Addressing Services

Internet Protocol Version 6Internet Protocol Version 6IPv6IPv6

CCNA4-3 Chapter 7-2

IPv6 – Why We Need More Address Space IPv6 – Why We Need More Address Space

• The IPv4 address space provides approximately The IPv4 address space provides approximately 4,294,967,2964,294,967,296 unique addresses. unique addresses.

• Only 3.7 billion addresses are assignableOnly 3.7 billion addresses are assignable..• Separates the addresses into classes.Separates the addresses into classes.• Reserves addresses for multicasting, testing, and Reserves addresses for multicasting, testing, and

other specific uses.other specific uses.• As of As of January, 2007January, 2007, approximately , approximately 2.4 billion2.4 billion of the of the

available IPv4 addresses are available IPv4 addresses are already assignedalready assigned to end to end users or ISPs.users or ISPs.

• Despite the large number, IPv4 address space is Despite the large number, IPv4 address space is running out.running out.

CCNA4-4 Chapter 7-2

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63

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80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111

112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127

128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143

144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159

160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175

176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191

192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207

208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223

224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239

240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255


IPv4 Address AllocationIPv4 Address AllocationIPv4 Address AllocationIPv4 Address Allocation

UnavailableUnavailableUnavailableUnavailable

AllocatedAllocatedAllocatedAllocated

AvailableAvailableAvailableAvailable

16,777,216 16,777,216 addressesaddresses


1993199319931993

CCNA4-5 Chapter 7-2

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208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223

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240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255








2000200020002000

CCNA4-6 Chapter 7-2

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112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127

128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143

144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159

160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175

176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191

192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207

208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223

224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239

240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255








2007200720072007

CCNA4-7 Chapter 7-2

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64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79

80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111

112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127

128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143

144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159

160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175

176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191

192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207

208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223

224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239

240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255


AugustAugust20092009

AugustAugust20092009







http://www.personal.psu.edu/dvm105/blogs/ipv6/http://www.personal.psu.edu/dvm105/blogs/ipv6/http://www.personal.psu.edu/dvm105/blogs/ipv6/http://www.personal.psu.edu/dvm105/blogs/ipv6/

CCNA4-8 Chapter 7-2

IPv6 – Why Is Address Space Shrinking? IPv6 – Why Is Address Space Shrinking?

• Population Growth:Population Growth:• The Internet population is growing.The Internet population is growing.• November 2005, Cisco estimate: 973 million users.November 2005, Cisco estimate: 973 million users.• This number has doubled since then.This number has doubled since then.

• Users stay on longer.Users stay on longer.• Reserve IP addresses for longer periods.Reserve IP addresses for longer periods.• Contacting more and more peers daily.Contacting more and more peers daily.

• Mobile Users:Mobile Users:• More than one billion mobile phones.More than one billion mobile phones.• More than 20 million IP-enabled mobile devices.More than 20 million IP-enabled mobile devices.

CCNA4-9 Chapter 7-2

IPv6 – Why Is Address Space Shrinking?IPv6 – Why Is Address Space Shrinking?

• Transportation:Transportation:• There will be more than one billionThere will be more than one billion

automobiles by 2008.automobiles by 2008.• Newer models are IP-enabled to allow remote Newer models are IP-enabled to allow remote

monitoring.monitoring.• Consumer Electronics:Consumer Electronics:

• The newest home appliances allow remote monitoring The newest home appliances allow remote monitoring using IP technology.using IP technology.• e.g.e.g. Digital Video Recorders Digital Video Recorders (DVRs)(DVRs) that download that download

and update program guides.and update program guides.• Home networking.Home networking.

CCNA4-10 Chapter 7-2

Reasons for Using IPv6 Reasons for Using IPv6

• The ability toThe ability to scale networks for future demands scale networks for future demands requires a requires a limitless supply of IP addresses and improved mobility.limitless supply of IP addresses and improved mobility.

• DHCP and NAT aloneDHCP and NAT alone cannot meet these requirements. cannot meet these requirements.• IPv6 satisfiesIPv6 satisfies

the increasinglythe increasinglycomplexcomplexrequirementsrequirementsof hierarchicalof hierarchicaladdressingaddressingthat IPv4 doesthat IPv4 doesnot provide.not provide.



• Address Availability:Address Availability:• IPv4:IPv4: 4 octets - 32 bits 4 octets - 32 bits

• 2^32 or 2^32 or 4,294,467,2954,294,467,295 IP Addresses. IP Addresses.

• IPv6:IPv6: 16 octets - 128 bits 16 octets - 128 bits• 3.4 x 10^38 or3.4 x 10^38 or

340,282,366,920,938,463,463,374,607,431,768,211,456340,282,366,920,938,463,463,374,607,431,768,211,456

(340 undecillion)(340 undecillion) IP Addresses.IP Addresses.

• Every atom of every person on EarthEvery atom of every person on Earth could be assigned could be assigned 7 unique addresses7 unique addresses with some to sparewith some to spare (assuming (assuming7 × 107 × 102727 atoms per human x 6.5 Billion) atoms per human x 6.5 Billion)..



• IPv6 Advanced Features:IPv6 Advanced Features:


IPv6 AddressingIPv6 Addressing

CharacteristicCharacteristic IPv4IPv4 IPv6IPv6

Format

x.x.x.x

4, 8-bit fields

Separated by dots

x:x:x:x:x:x:x:x

8, 16-bit fields

Separated by colons

Field Representation

Decimal FormatGroups of 4 hexadecimal digits, case sensitive forA, B, C, D, E and F.

Leading Zeroes Omitted Optional

Successive Zero Fields

Must be includedCan be represented by “::” once in an address.



• IPv6 Representation – Rule 1:IPv6 Representation – Rule 1:• The leading zeroesThe leading zeroes in any 16-bit segment do not have to in any 16-bit segment do not have to

be written. If any 16-bit segment has be written. If any 16-bit segment has fewer than four fewer than four hexadecimal digitshexadecimal digits, it is assumed that the , it is assumed that the missing digits missing digits are leading zeroesare leading zeroes..

2031 : 0000 : 130F : 0000 : 0000 : 09C0 : 876A : 130B

2031 : 0 : 130F : 0 : 0 : 9C0 : 876A : BC00

8105 : 0000 : 0000 : 4B10 : 1000 : 0000 : 0000 : 0005

8105 : 0 : 0 : 4B10 : 1000 : 0 : 0 : 5

0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000

0 : 0 : 0 : 0 : 0 : 0 : 0 : 0



• IPv6 Representation – Rule 2:IPv6 Representation – Rule 2:• Any single,Any single, contiguous string of one or more contiguous string of one or more 16-bit 16-bit

segments consisting of segments consisting of all zeroesall zeroes can be represented can be represented onceonce with a with a double colondouble colon..

1080:0:0:0:8:800:200C:417A = 1080::8:800:200C:417A

FF01:0:0:0:0:0:0:101 = FF01::101

0:0:0:0:0:0:0:1 = ::1

0:0:0:0:0:0:0:0 = ::



• IPv6 Representation – Rule 2:IPv6 Representation – Rule 2:• Any single,Any single, contiguous string of one or more contiguous string of one or more 16-bit 16-bit

segments consisting of segments consisting of all zeroesall zeroes can be represented can be represented onceonce with a with a double colondouble colon..

Example:Example: 1843:f01 1843:f01::::2222::::fafa

• IllegalIllegal because the length of the two all-zero strings is because the length of the two all-zero strings is ambiguousambiguous..

1843:00f0:1843:00f0:0000:00000000:0000:0022::0022:0000:00000000:0000:00fa:00fa

1843:00f0:1843:00f0:0000:0000:00000000:0000:0000:0022::0022:00000000:00fa:00fa

1843:00f0:1843:00f0:00000000:0022::0022:0000:0000:00000000:0000:0000:00fa:00fa

oror

oror



• IPv6 Representation:IPv6 Representation:• Prefix:Prefix:

• IPv4 IPv4 prefix (the network portion of the address) can prefix (the network portion of the address) can be be dotted decimaldotted decimal or or bit countbit count..

• e.g. e.g. 198.10.0.0 198.10.0.0 255.255.255.0255.255.255.0 oror /16/16

• IPv6 IPv6 prefix is always represented by prefix is always represented by bit countbit count..• e.g. e.g. 3ef8:ca62:12:cc3ef8:ca62:12:cc::2::2/64/64 16 32 48 64 16 32 48 64



• IPv6 Representation:IPv6 Representation:• In a URLIn a URL, it is enclosed in brackets., it is enclosed in brackets.

• http://http://[2001:1:4F3A::206:AE14][2001:1:4F3A::206:AE14]:8080/index.html:8080/index.html• URL parsers have to be modified.URL parsers have to be modified.• Cumbersome for users.Cumbersome for users.

• Mostly for diagnostic purposes.Mostly for diagnostic purposes.• Use Fully Qualified Domain Names Use Fully Qualified Domain Names (FQDN)(FQDN)..• DNS MUST WORK!DNS MUST WORK!



• IPV6 Address Types:IPV6 Address Types:• Unicast:Unicast:

• Global Unicast Address.Global Unicast Address.• Link Local Unicast.Link Local Unicast.• Unique Local Unicast.Unique Local Unicast.

• Multicast.Multicast.• Anycast.Anycast.

• Unlike IPv4, there isUnlike IPv4, there is no broadcast address no broadcast address..• There is an There is an “all nodes multicast”“all nodes multicast” which serves the same which serves the same

purpose.purpose.



• Unicast Addressing:Unicast Addressing:• A A unicast addressunicast address is an address that identifies a is an address that identifies a single single

devicedevice..• A A global unicast addressglobal unicast address is a unicast address that is is a unicast address that is

globally uniqueglobally unique..• Can be routed globally with Can be routed globally with no modificationno modification..

• How do we make a device How do we make a device globally identifiableglobally identifiable??



• Global Unicast Address:Global Unicast Address:• How do we make a device How do we make a device globally identifiableglobally identifiable??

• The host portion of the address is called the The host portion of the address is called the Interface IDInterface ID..• Can contain:Can contain:

• The interface’s 48-bit MAC Address.The interface’s 48-bit MAC Address.• An identifier derived from the EUI-64 Address An identifier derived from the EUI-64 Address

(more later).(more later).• A manually configured address.A manually configured address.



• Global Unicast Address:Global Unicast Address:• How do we make a device How do we make a device globally identifiableglobally identifiable??

• The host portion of the address is called the The host portion of the address is called the Interface IDInterface ID..• Address Address more correctly identifies an interfacemore correctly identifies an interface on a on a

host than a host itself. host than a host itself. • AA single single interface can have interface can have multiple IPv6 addresses multiple IPv6 addresses, ,

and can have anand can have an IPv4 address IPv4 address in addition. in addition.


• Global Unicast Address:Global Unicast Address:• So, how do we make this address So, how do we make this address globally routableglobally routable??

• Well, what is theWell, what is the hierarchy hierarchy we have to look at to do it? we have to look at to do it?

DeviceDeviceDeviceDevice

DeviceDeviceDeviceDeviceSubnetSubnetSubnetSubnet

SubnetSubnetSubnetSubnet


SiteSiteSiteSite

SiteSiteSiteSiteISPISPISPISP

ISPISPISPISPLIRLIRLIRLIRLIRLIRLIRLIR

RIRRIRRIRRIRRIRRIRRIRRIR

ICANNICANNICANNICANN



• We’ll divide the We’ll divide the network portionnetwork portion so that there is room for: so that there is room for:• The individual The individual sitesite administrator to add administrator to add subnetssubnets..• The remainder of the network portion will identify the The remainder of the network portion will identify the

remainder of the hierarchyremainder of the hierarchy..




• Using 16 bits for the Subnet-ID allows 65,536 separate Using 16 bits for the Subnet-ID allows 65,536 separate subnets…..(that subnets…..(that mightmight be enough)… be enough)…




• Making the Making the Subnet IDSubnet ID a a part of the network portionpart of the network portion creates a clear separation of functions. creates a clear separation of functions. • The The network portionnetwork portion provides the location of a device provides the location of a device

down to the specific data link. down to the specific data link. • The The host portionhost portion provides the identity of the device on provides the identity of the device on

the data link.the data link.




• So, what do we have left?So, what do we have left?



• IPv6 Global Unicast Address:IPv6 Global Unicast Address:• To understand the prefix, we need to know the To understand the prefix, we need to know the function function

of each organizationof each organization in the hierarchy. in the hierarchy.• ICANNICANN (Internet Corporation for Assigned Names and (Internet Corporation for Assigned Names and

Numbers):Numbers):• ManagesManages

the the DNSDNSRoot Zone.Root Zone.

• CoordinatesCoordinatesthe the globalglobalIP and AS number spaceIP and AS number space and assigns them to the and assigns them to the RIRs.RIRs.




of each organizationof each organization in the hierarchy. in the hierarchy.• RIRRIR (Regional Internet Registry): (Regional Internet Registry):

• OverseesOverseesallocationallocationandandregistrationregistrationof Internetof Internetnumber resources within a number resources within a particular regionparticular region of the of the world.world.• IP addresses (both IPv4 and IPv6) and IP addresses (both IPv4 and IPv6) and

autonomous system numbers.autonomous system numbers.




• IPv6 Global Unicast Address:IPv6 Global Unicast Address:• RIRRIR

(Regional Internet Registry):(Regional Internet Registry):

AfriNICAfriNIC Africa region

APNICAPNIC Asia and Pacific region

ARINARINCanada, many Caribbean and North Atlantic islands, and the United States

LACNICLACNIC Latin America and parts of the Caribbean

RIPE NCCRIPE NCC Europe, Parts of Asia and the Middle East




of each organizationof each organization in the hierarchy. in the hierarchy.• LIRLIR (Local Internet Registry): (Local Internet Registry):

• UsuallyUsuallylargelargeInternetInternetServiceServiceProviders.Providers.

• Received an IP address allocation from a Regional Received an IP address allocation from a Regional Internet Registry (RIR).Internet Registry (RIR).

• May assign parts of this allocation to its own May assign parts of this allocation to its own customers or smaller ISPs.customers or smaller ISPs.




of each organizationof each organization in the hierarchy. in the hierarchy.• ISPISP (Internet Service Provider): (Internet Service Provider):

• A companyA companythat offersthat offersitsitscustomerscustomersaccess toaccess tothe Internet.the Internet.

• The ISP connects to its customers using an The ISP connects to its customers using an appropriate data transmission technology.appropriate data transmission technology.




of each organizationof each organization in the hierarchy. in the hierarchy.• SiteSite::

• The endThe endcustomer ofcustomer ofan ISP.an ISP.

• Can beCan beindividualsindividualsor corporations requiring Internet access. or corporations requiring Internet access.



• IPv6 Global Unicast Address:IPv6 Global Unicast Address:• So, how do we make this address So, how do we make this address globally routableglobally routable??

• With very few exceptions:With very few exceptions:• Interface ID is 64 bits.Interface ID is 64 bits.• Subnet ID is 16 bits. Subnet ID is 16 bits.

• TheThe ICANN ICANN and the Regional Internet Registries and the Regional Internet Registries (RIRs) (RIRs) assign IPv6 prefixes assign IPv6 prefixes (normally /23)(normally /23) to the Local Internet to the Local Internet Registries Registries (LIRs)(LIRs). .




• The LIRs and ISPsThe LIRs and ISPsthen allocate longerthen allocate longerprefixes to theirprefixes to theircustomers.customers.

• In the majority of cases, the prefixes assigned are In the majority of cases, the prefixes assigned are /48/48. .




• Begins with Begins with binary 001binary 001..• More easily recognized as beginning with a hexadecimal More easily recognized as beginning with a hexadecimal

2 or 3. 2 or 3.

0010 xxxx or 0011 xxxx0010 xxxx or 0011 xxxx• ICANN assigns global unicast IPv6 addresses as ICANN assigns global unicast IPv6 addresses as public public

and globally-uniqueand globally-unique IPv6 addresses. IPv6 addresses. • No need for NAT.No need for NAT.




ICANN or ICANN or RIR - /23RIR - /23ICANN or ICANN or RIR - /23RIR - /23



• Reserved Addresses:Reserved Addresses:• A portion of the IPv6 address space is reserved for A portion of the IPv6 address space is reserved for

various uses, both present and future.various uses, both present and future.

Address TypeAddress Type High Order Bits (Binary)High Order Bits (Binary) High-Order Bits (Hex)High-Order Bits (Hex)

Unspecified 00…0 ::/128

Loopback 00…1 ::1/128

Multicast 11111111… FF00::/8

Link Local Unicast 1111111010 FE80::/10

Global Unicast 001 2xxx::/4 or 3xxx::/4

Reserved (Future Global unicast)

Everything Else

FYIFYI



• Unspecified Addresses (::/128):Unspecified Addresses (::/128):• In IPv4, an IP address of all zeroes has a special In IPv4, an IP address of all zeroes has a special

meaning:meaning:• In a host, In a host, it refers to the host itselfit refers to the host itself, and is used when , and is used when

a device does not know its own address.a device does not know its own address.• In IPv6, this concept has been formalized, and the all-In IPv6, this concept has been formalized, and the all-

zeroes addresszeroes address (0:0:0:0:0:0:0:0) (0:0:0:0:0:0:0:0) is named the is named the "unspecified""unspecified" address. address.

• It is typically used in the It is typically used in the source field of a datagramsource field of a datagram that is sent by a device that that is sent by a device that seeks to have its IP seeks to have its IP address configuredaddress configured..



• Loopback Address (::1/128):Loopback Address (::1/128):• Just as in IPv4, a provision has been made for a special Just as in IPv4, a provision has been made for a special

loopback IPv6 address.loopback IPv6 address.• Datagrams sent to this address "loop back" to the Datagrams sent to this address "loop back" to the

sending device.sending device.• In IPv6 there is In IPv6 there is just one addressjust one address, not a whole block, , not a whole block,

for this function.for this function.



• Link Local Unicast Address (FE80::/10):Link Local Unicast Address (FE80::/10):• NewNew to the concept of addressing with IP. to the concept of addressing with IP.

• These addresses refer These addresses refer only to a particular physical only to a particular physical networknetwork..

• Routers do not forwardRouters do not forward datagrams using link-local datagrams using link-local addresses.addresses.

• They are only for They are only for local communicationlocal communication on a particular on a particular physical physical network segmentnetwork segment..• Automatic address configuration.Automatic address configuration.• Neighbor discovery.Neighbor discovery.• Router discovery.Router discovery.• IPv6 Routing Protocols. IPv6 Routing Protocols.



• Multicast Address(FF00::/8):Multicast Address(FF00::/8):• A multicast address A multicast address identifies a multicast groupidentifies a multicast group (set of (set of

devices). devices). • A packet being sent to a multicast group is originated by A packet being sent to a multicast group is originated by

a single device.a single device.• A multicast packet normally has a A multicast packet normally has a unicast address as unicast address as

its source addressits source address and a and a multicast address as its multicast address as its destinationdestination address. address.

• A multicast address A multicast address never appears in a packet as a never appears in a packet as a source addresssource address..

• There is no reserved broadcast address like IPv4.There is no reserved broadcast address like IPv4.



• Multicast Address(FF00::/8):Multicast Address(FF00::/8):• Examples of well-known IPv6 Multicast AddressesExamples of well-known IPv6 Multicast Addresses

AddressAddress Multicast GroupMulticast Group

FF02::1 All Nodes

FF02::2 All Routers

FF02::5 OSPFv3 Routers

FF02::6 OSPFv3 Designated Routers

FF02::9 RIPng Routers

FF02::A EIGRP Routers

FF02::B Mobile Agents

FF02:C DHCP Servers / Relay Agents

FF02::D All PIM Routers

FYIFYI


IPv6 Address ManagementIPv6 Address Management

• IPv6 addresses use IPv6 addresses use Interface IdentifiersInterface Identifiers to identify interfaces to identify interfaces on a link.on a link.

• Think of them as the Think of them as the host portionhost portion of an IPv6 address. of an IPv6 address.• They They must be uniquemust be unique on a specific link. on a specific link.• They are They are always 64 bitsalways 64 bits and can be and can be dynamicallydynamically derived derived

from a Layer 2 address (MAC).from a Layer 2 address (MAC).• Four methods of address assignment:Four methods of address assignment:

• Static Static assignment using a assignment using a manual interface IDmanual interface ID. . • Static Static assignment using an assignment using an EUI-64 interface IDEUI-64 interface ID. . • DynamicDynamic StatelessStateless AutoconfigurationAutoconfiguration..• DymanicDymanic DHCP for IPv6 DHCP for IPv6 (DHCPv6)(DHCPv6)



• Static Static assignment using a assignment using a manual interface IDmanual interface ID..• Manually assign both the prefix (network) and interface Manually assign both the prefix (network) and interface

ID (host) portion of the IPv6 address.ID (host) portion of the IPv6 address.• To configure an IPv6 address on a Cisco router To configure an IPv6 address on a Cisco router

interface, use the interface, use the ipv6 addressipv6 address command in interface command in interface configuration mode.configuration mode.

R1(config-if)#ipv6 address R1(config-if)#ipv6 address 2001:DB8:2222:7272::72/642001:DB8:2222:7272::72/64



• StaticStatic assignment using an assignment using an EUI-64 interface IDEUI-64 interface ID..• The The EUI-64 standardEUI-64 standard

explains how toexplains how tostretch IEEE 802stretch IEEE 802MAC addresses fromMAC addresses from48 to 64 bits by48 to 64 bits byinserting the inserting the 16-bit16-bit0xFFFE 0xFFFE in the middlein the middleat the 24th bitat the 24th bit of the MAC address to create a 64-bit, of the MAC address to create a 64-bit, unique interface identifier.unique interface identifier.

R1(config-if)#ipv6 address R1(config-if)#ipv6 address 2001:DB8:2222:7272::/64 eui-642001:DB8:2222:7272::/64 eui-64



• DynamicDynamic StatelessStateless AutoconfigurationAutoconfiguration::• Autoconfiguration automatically configures the IPv6 Autoconfiguration automatically configures the IPv6

address.address.• The autoconfiguration mechanism was introduced to The autoconfiguration mechanism was introduced to

enable plug-and-play networkingenable plug-and-play networking of these devices to help of these devices to help reduce administration overhead.reduce administration overhead.

• Uses IPv6 Uses IPv6 NDPNDP (Neighbor Discovery Protocol) router (Neighbor Discovery Protocol) router solicitation and router advertisement messages to obtain solicitation and router advertisement messages to obtain the information. the information.



• Dynamic Stateless Autoconfiguration:

1. The router interface has been configured with an IPv6 address.

2. A device entering the network will query the router for its address using ICMPv6 to exchange Neighbor Discovery Protocol (NDP) messages.

3. The router will respond with its address and the device will use:

• The Global Routing Prefix (64 bits) from the router address.

• EUI-64 to add the device’s MAC address.

FYIFYI



• DynamicDynamic StatelessStateless AutoconfigurationAutoconfiguration: Using EUI-64.: Using EUI-64.

FYIFYI



• DynamicDynamic DHCPv6 for IPv6DHCPv6 for IPv6::• Similar DHCP for IPv4.Similar DHCP for IPv4.

• Host sends a Host sends a multicastmulticast packet searching for the packet searching for the DHCP server. DHCP server.

• DHCP DHCP server repliesserver replies..• DHCP DHCP clientclient sends a message sends a message asking for a leaseasking for a lease of of

an IP address.an IP address.• DHCP DHCP server repliesserver replies, listing an IPv6 address, prefix , listing an IPv6 address, prefix

length, default router, and DNS IP addresses. length, default router, and DNS IP addresses. • DHCPv4 and DHCPv6 actually differ in detail, but the DHCPv4 and DHCPv6 actually differ in detail, but the

basic process remains the samebasic process remains the same..


IPv6 Transition StrategiesIPv6 Transition Strategies



• Dual Stack:Dual Stack:• Method in which a node has implementation and Method in which a node has implementation and

connectivity to connectivity to both an IPv4 and IPv6both an IPv4 and IPv6 network. network.• TheThe recommended recommended option. option.• Involves running IPv4 and IPv6 at the same timeInvolves running IPv4 and IPv6 at the same time..

• Tunneling (4 Methods):Tunneling (4 Methods):

• Manual IPv6-over-IPv4 tunneling:Manual IPv6-over-IPv4 tunneling:• An IPv6 packet is encapsulated within the IPv4 An IPv6 packet is encapsulated within the IPv4

protocol. This method requires dual-stack routers.protocol. This method requires dual-stack routers.




• Dynamic 6to4 tunneling:Dynamic 6to4 tunneling:• Automatically establishes the connection Automatically establishes the connection of IPv6 of IPv6

islandsislands through an IPv4 network, typically the through an IPv4 network, typically the Internet.Internet.

• It It dynamically applies a valid, unique IPv6 prefixdynamically applies a valid, unique IPv6 prefix to to each IPv6 island, which enables the fast deployment each IPv6 island, which enables the fast deployment of IPv6 in a corporate network without address of IPv6 in a corporate network without address retrieval from the ISPs or registries.retrieval from the ISPs or registries.




• Intra-Site Automatic Tunnel Addressing Protocol Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)(ISATAP) tunneling: tunneling:• Creates a virtual IPv6 network over an IPv4 Creates a virtual IPv6 network over an IPv4

infrastructure.infrastructure.

• Teredo tunneling:Teredo tunneling:• Provides host-to-host automatic tunneling instead of Provides host-to-host automatic tunneling instead of

gateway tunneling. gateway tunneling.

FYIFYI



• NAT-Protocol Translation NAT-Protocol Translation (NAT-PT)(NAT-PT)::• Cisco IOS Release 12.3(2)T and later (with the Cisco IOS Release 12.3(2)T and later (with the

appropriate feature set) also include NAT-PT between appropriate feature set) also include NAT-PT between IPv6 and IPv4.IPv6 and IPv4.

• This translationThis translation allows direct communication allows direct communication between between hosts that use hosts that use different versions of the IP protocoldifferent versions of the IP protocol..

• These translations are more complex than IPv4 NAT.These translations are more complex than IPv4 NAT.• At this time, this translation technique is theAt this time, this translation technique is the least least

favorable optionfavorable option and should be used as a and should be used as a last resortlast resort..


Cisco IOS Dual StackCisco IOS Dual Stack

• Dual StackingDual Stacking is an integration method that allows a node to is an integration method that allows a node to have have simultaneous connectivitysimultaneous connectivity to an IPv4 and IPv6 network. to an IPv4 and IPv6 network.

• Each node hasEach node has two protocol stacks two protocol stacks with the configuration on with the configuration on the the same interface or on multiple interfacessame interface or on multiple interfaces..


Cisco IOS Dual StackCisco IOS Dual Stack

• If If both IPv4 and IPv6both IPv4 and IPv6 addresses are configured on an addresses are configured on an interface, the interface is considered interface, the interface is considered dual stackeddual stacked..


IPv6 TunnelingIPv6 Tunneling

• Tunneling is an integration method where an Tunneling is an integration method where an IPv6 packet is IPv6 packet is encapsulated within another protocolencapsulated within another protocol. .

• This is This is considered dual stackingconsidered dual stacking..• Tunneling encapsulates the IPv6 packet in the IPv4 packet. Tunneling encapsulates the IPv6 packet in the IPv4 packet.



• When IPv4 is used to encapsulate the IPv6 packet:When IPv4 is used to encapsulate the IPv6 packet:• Protocol type of Protocol type of 4141..• 20-byte IPv4 header20-byte IPv4 header with no options. with no options.• IPv6 header and payload.IPv6 header and payload.• Requires Requires dual stackeddual stacked routers. routers.



• Manually Configured IPv6 Tunnel:Manually Configured IPv6 Tunnel:• Equivalent to a Equivalent to a permanent link between two IPv6 permanent link between two IPv6

domains over an domains over an IPv4 backbone.IPv4 backbone.• The primary use is for stable connections that require The primary use is for stable connections that require

regular, secure communication:regular, secure communication:• Between two edge routers.Between two edge routers.• Between an end system and an edge router.Between an end system and an edge router.• For connection to remote IPv6 networks.For connection to remote IPv6 networks.


Routing Configurations with IPv6Routing Configurations with IPv6

• Like IPv4 classless inter-domain routing (CIDR), IPv6 uses Like IPv4 classless inter-domain routing (CIDR), IPv6 uses longest prefix matchlongest prefix match routing. routing.

• The IPv6 larger address spaces make room forThe IPv6 larger address spaces make room for large large address allocationsaddress allocations to ISPs and organizations. to ISPs and organizations.

• An ISP aggregates all of the prefixesAn ISP aggregates all of the prefixes of its customers of its customers into a single prefix and into a single prefix and announces the single prefixannounces the single prefix to the to the IPv6 Internet.IPv6 Internet.

• The increased address space is sufficient to allow The increased address space is sufficient to allow organizations to define aorganizations to define a single prefix for their entire single prefix for their entire networknetwork..

• How does this affect router performance?How does this affect router performance?



• How a router functions in a network.How a router functions in a network.

Control Control PlanePlane

Control Control PlanePlane



• How a router functions in a networkHow a router functions in a network..• Control Plane:Control Plane:

• Handles theHandles the interaction of the interaction of therouter router with the other networkwith the other networkelements.elements.

• Provides theProvides the information information for:for:• DecisionsDecisions..• Control the Control the overall router operationoverall router operation..

• Routing protocols.Routing protocols.• Network management. Network management.




• IPv6 Address Size:IPv6 Address Size:• May perform slower thanMay perform slower than

IPv4 depending on theIPv4 depending on thenumber of cycles number of cycles it takes to process the new it takes to process the new address.address.

• Multiple Ipv6 Node Addresses:Multiple Ipv6 Node Addresses:• Because IPv6 nodes can use Because IPv6 nodes can use several IPv6 unicast several IPv6 unicast

addressesaddresses, , memory consumptionmemory consumption of the Neighbor of the Neighbor Discovery cache may be affected.Discovery cache may be affected.




• Ipv6 Routing Protocols:Ipv6 Routing Protocols:• IPv6 routing protocols areIPv6 routing protocols are

similar to their IPv4similar to their IPv4counterparts, but since an counterparts, but since an IPv6 prefix is four times IPv6 prefix is four times largerlarger than an IPv4 prefix, than an IPv4 prefix, routing updates routing updates have to have to carry more information.carry more information.

• IPv6 Routing Table Size:IPv6 Routing Table Size:• Increased IPv6 address space implies Increased IPv6 address space implies larger larger

routing tables and higher memory requirementsrouting tables and higher memory requirements to to support them. support them.



• How a router functions in a networkHow a router functions in a network..• Data Plane:Data Plane:

• Handles Handles packet forwardingpacket forwardingfrom one physical or logicalfrom one physical or logicalinterface to another.interface to another.

• Enhanced Services:Enhanced Services:• Include Include advanced featuresadvanced features applied when forwarding applied when forwarding

data:data:• Packet filtering (ACLS).Packet filtering (ACLS).• Quality of Service (QoS).Quality of Service (QoS).• Encryption.Encryption.• Translation and accounting. Translation and accounting.



• How a router functions in a networkHow a router functions in a network..• Data Plane and EnhancedData Plane and Enhanced

Services:Services:• Parsing IPV6 Headers:Parsing IPV6 Headers:

• ApplicationsApplications, including, includingmobile IPv6, often use IPv6 address information in mobile IPv6, often use IPv6 address information in extension headersextension headers. Additional fields require . Additional fields require additional processing.additional processing.

• For example, an For example, an ACLACL used to filter Layer 4 (ports) used to filter Layer 4 (ports) must apply the filter must apply the filter to all packetsto all packets..• If theIf the length of the extension header is larger length of the extension header is larger

than the router can handlethan the router can handle it will severely affect it will severely affect the forwarding performance of the router.the forwarding performance of the router.



• How a router functions in a networkHow a router functions in a network..• Data Plane and EnhancedData Plane and Enhanced

Services:Services:• IPv6 Address Lookup:IPv6 Address Lookup:

• IPv6 performs a lookup onIPv6 performs a lookup onpackets entering the router to fpackets entering the router to find the correct output ind the correct output interfaceinterface..

• IPv4 - parses aIPv4 - parses a 32-bit 32-bit destination address. destination address.• IPv6 - parses a IPv6 - parses a 128-bit128-bit destination address. destination address.• Application-Specific Integrated Circuit Application-Specific Integrated Circuit (ASIC) (ASIC)

originally designed for IPv4originally designed for IPv4..• Could result in sending packets into Could result in sending packets into slower software slower software

processingprocessing or or dropping themdropping them..


RIPng Routing ProtocolRIPng Routing Protocol

• Routing Information Protocol next-generationRouting Information Protocol next-generation (RIPng) (RIPng)::• Based on RIPv2:Based on RIPv2:

• Distance Vector.Distance Vector.• Limit of 15 hops.Limit of 15 hops.• Split Horizon and Poison Reverse.Split Horizon and Poison Reverse.• Only neighboring routers exchange local messages.Only neighboring routers exchange local messages.• Updates on UDP port 521.Updates on UDP port 521.

• Updated features:Updated features:• IPv6 prefix and next hop address.IPv6 prefix and next hop address.• Uses Uses multicast group FF02::9multicast group FF02::9 as the destination for as the destination for

all RIP updates.all RIP updates.• Supported on Cisco 12.2(2)T and later.Supported on Cisco 12.2(2)T and later.


RIPng Routing ProtocolRIPng Routing Protocol

FeatureFeature RIPv2RIPv2 RIPngRIPng

Advertises routes for… IPv4 IPv6

Layer 3 / 4 Protocols IPv4 / UDP IPv6 / UDP

UDP Port 520 521

Distance Vector Yes Yes

Default Administrative Distance 120 120

Supports VLSM Yes Yes

Automatic Summarization Yes N/A

Uses Split Horizon / Poison Reverse Yes Yes

30 Second Periodic Full Updates Yes Yes

Uses Hop Count Metric Yes Yes

Metric Meaning Infinity 16 16

Multicast Update Destination 224.0.0.9 FF02::9


Configuring IPv6 AddressesConfiguring IPv6 Addresses

• Enabling IPv6 on Cisco Routers:Enabling IPv6 on Cisco Routers: Static or eui-64Static or eui-64Static or eui-64Static or eui-64

Device Mac = 0260:3E47:1530Device Mac = 0260:3E47:1530Device Mac = 0260:3E47:1530Device Mac = 0260:3E47:1530



• Cisco IOS IPv6 name resolution:Cisco IOS IPv6 name resolution:• Define a static name for an IPv6 address using the Define a static name for an IPv6 address using the

command:command:

ipv6 host name [port] ipv6-address1ipv6 host name [port] ipv6-address1[ipv6-address2...ipv6-address4][ipv6-address2...ipv6-address4]

• You can define up to four IPv6 addresses for one You can define up to four IPv6 addresses for one hostname.hostname.

• The port option refers to the Telnet port to be used for The port option refers to the Telnet port to be used for the associated host.the associated host.



• Cisco IOS IPv6 name resolution:Cisco IOS IPv6 name resolution:• Specify the DNS server used by the router with the Specify the DNS server used by the router with the

command:command:

ip name-server addressip name-server address

• The address can be an IPv4 or IPv6 address.The address can be an IPv4 or IPv6 address.• You can specify up to six DNS servers with this You can specify up to six DNS servers with this

command.command.


Configuring RIPng with IPv6Configuring RIPng with IPv6

• When configuring supported routing protocols in IPv6, you When configuring supported routing protocols in IPv6, you must:must:

• CreateCreate the routing process. the routing process.

Router(config)#Router(config)#ipv6 unicast routingipv6 unicast routing

Router(config)#Router(config)#ipv6 router rip ipv6 router rip namename

• EnableEnable the routing process on interfaces. the routing process on interfaces.

Router(config-if)Router(config-if)#ipv6 rip #ipv6 rip namename enable enable


Configuring RIPng with IPv6Configuring RIPng with IPv6


Verifying RIPng with IPv6Verifying RIPng with IPv6


Troubleshooting RIPng with IPv6Troubleshooting RIPng with IPv6

ccna4-1 chapter 7-2 chapter 7 ip addressing services part ii

Documents

ipv4 address space

available ipv4 addresses

unique addresses

ipv6 slide

large number

specific uses